Process of surfacing highways



July 21,` 1925.

c. R. HUNT PROCESS OF SURFACING' HIGHWAYS Filed sept. 12

, 1921 2 Sheets-Sheet l July 21, 1925.

C. R. HUNT PROCESS OF SURFACING HIGHWAYS Filed sept. 12,v 1921 2 Smets-sheet 2 00/ erf H /77 Patented July 21,

UNITED s'rA'rEs PATENT OFFICE.

esima* a. num', or Kansas cmfmssoimr.

PROCES I BUBFACING BIGHWAYB.

Anuman mea september 1a, 1921. serial no. 500,104.

To all whom 'it may concern.'

- Be it known that I, CALvnn'r R. HUNT, a citlzen of the United States, residing at Kansas City, in the county of Jackson. and State of Missouri, have invented certain new and useful Improvements in Processes of Surfacing Highways; and I do declare the following to be a ull, .clear,`and exact def scri tion of the invention, such as will ena le others skilled in the art to which it appertains to makeand use the same, reference being had to the accom anying drawings, and to the figures of re erence marked thereon, which form a part of this specification.

This invention relates to highways and particularly to a method for making the same. v

The primary object of the invention is to construct a highway sich as a -road or the 11ke,in a comparatlvely ine nsive man-4 ner but which will have consi erable dura- The novel manner of carrying out the in-V vention will be apparent hereinafter, reference bein hitld to the accompanying drawm w c Vig. 1 is a view showing the stepof re' `m'oving the earth from the trench. l

" Fig. 2 is a view showing .the trench crowned and compacted.

Fig. 3 is a view showing the application of a ayer of moisture-impervious material for closing the capillaries and voids.

Fig. 4 1s a view showin some of the material redistributed into t e trench and treated with a moisture-proof binder.

Fig. 5 is a view showin the material beg turned over to mix t e same with the binder.

Fig. 6 is a view showing the material bei in pulverlzed.

1g. 7 is aview showin ythe mixed binder and earth being comp or tamped.

Fig. 8 is a view showing the application of a sealing coat.

F1 9 is a view showing the application of a ishing coat, and

F ing ally rolled.

-n carrying out the invention I prefer to pregare a trench 1 by plowing to the desire depth andthen pulverizing the p1owed 11E eart which may be removed by a. suita le means, as a road grader 2, and piled i is a view showing the highway be' upon the shoulders 3 or in the side ditches 4 (see Fig. 1).

The trench is then crowned to give the desired curvature 5, as shown in Fi 2, and this sub-grade 5 is then tampe rolled, or both, until the surface ceases to yield.. I prefer to use a tamping-machine as indicated at 6 in Fig. 2v.

When the crown or sub-grade has been suitably compacted, I apply a sealing coat 7 or stratum of material impervious to moisture to seal the capillaries and voids and thereby prevent moisture from working up into the body of the road bed to be subsequently laid. I ind that liquid or plastic asphaltum 4admirably serves as a suitable medium for'the sealing coat -and I prefer to use asphaltum in the liquid form as itmore readily spreads land Vassociates itself with the crown.

The next step is to spread earth over the coat 7 in the form of a layer 8, shown in Fig. 4, referably for several inches. Any suitab e earth ymay be employed but for economy'I may utilize the previousl removed earth. Upon this earth thus lai as shown' in Fig. A4, I may apply a binder of suitable moisture-proof material as, for example, asphaltum, and this may be distributed by a orl spraying machine l94 of approved construction. l

I have' found that about one-fourth gallon per square yard of surface for each application is good After the the material is turned over by av suitable means as, for example, a spring toothed harrow 10, as shown in Flg. 5 and then a disk harrow 11 may pass'over the material. to pnlverize it." Then a second apphcaton of the binderl is af plied in the proportions of about one-fourt gallon per square yard. The material s'agam turned over a spring toothed barrow and then pulm'med Errgtctice.

application of the bmder,

' binder has been a by the disk'harrowy 11 or by some other suitable means and the application of the binder, the s ring harrow or its equivalent and the disk arrow or its equivalent is practiced until the requisite amount of binder is a plied, say about three gallons per square yar 'This amount may be varied, however, dependent upon the character of the earth forming the road bed.

When sufficient binder has been applied to the earth, itis kneaded by a suitable means, for example, a light Atam ing machine 12, 'shown in Fig. 7; a` goo example of tamping machine being shown in the patent to Ross and Deal, No. v891,954 of June 30, 1908. The vteeth on the tamping machine,'however, will have a relatively slight cross sectional area because the purpose at this stage of the process is to knead or thoroughly intermix the binder and the earth to -impregnate the earth with the binder.

When the earth has been lmeaded to the roper consistency, another stratum 'of earth 1s distributed over the surface and the steps outlined in Figs. 4, 5 and 6 are repeated, it being desirable, however, that the pulverizer for the second stratum will penetrate the irst so that there will-be an intermixed, homogeneous mass, forming the main body of the road and the kneadin'g tamper will, by preference, penetrate the second stratum into the first to eliminate stratification of the applied applications of the earth and binder.

The applications of layers of earth and binder, as well as the turning over, accord# ing to Fig. 5 and the pulverizing, according to Fig. 6, with the Almeading according to Fig. 7, may continue until the desired thickness of the road bed is reached. However,

ordinarily, two applications will be suiicient. 'v

Whe'n the final application of earth and plied, heavier tamping machines may be utilized to compact thel material within the trench 1 and the tamping ma continue until the road bed ceases to yie d, which is usually indicated by the fact that the tampin machines ride to the sur' face of the be Then a sealing coat of suitable material, such as ash altum, is ap-` lied, preferably about oneourth to onealf gallon per square yard of earth. The seallng coat 13 may be applied by a suitable machine, as indicated. at 14, Fig. 8.

In finishing the road bed I prefer to apply a finishing coat of earth, sand, gravel or Athe like about one-half inch thick, as indicated lat 15 in Fi 9, spreading the same over the surface o the top sealing coat and rolling bv a suitable machine, as indicated at 16 1n ig. 10. The highway is now finished. A

All important step in the process is to thorough y impregnate the earth with the nated with the binder. In order to effect an eicient impregnation it is necessary that the earth be thoroughly kneaded and I have found that a tamping machine-having tools of relatively small cross section, which will penetrate through the mass, mechanically forces the binder into the earth so that an ellicient impregnation takes place as distinguished from a mechanical-mixture. When the earth has become impregnated, it will thoroughl compact and form into a hard bed, there y providing an eiicient highway.

By utilizing the earth removed from the trench as the main body of the road bed, the construction can be carried on at a'relatively small cost and while I prefer to pulverize the material immediately after it is plowed and before it is thrown over on the shoulders or ditches to the side of the trench, this is not an essential step because the pulverizing may be conducted after the bottom sealing coat is applied to the trench and the earth moved back into it.

Attention is calledl to the fact that the tamping machines which compact the road bed tamp from the bottom toward the top because the tamping tool penetrates into the material and compacts it from the bottom progressively toward the surface at a uniform cross sectional density, the operation being finished when the tamping tools have floated to the top of the road bed due to the fact that the material ceases to yield under the action of the tools.

What I claim and desire to secure by Letters Patent is:

'1. The method of building roadways consisting of forming a base by compacting the 'earth between the lines of the roadway and coating the compacted earth with waterproofing material, introducing earth and asphaltum onto the base, compacting the mixture of earth and asphaltum from the bottom upwardly by repeated tampings, and applying a sealing substance to the top ofV the compacted mass.

2. The method of building roadways consisting of forming a base by compacting the earth between, the lines of the roadway and coating the compacted earth withI waterproofing material, introducing earth and asphaltum onto the base, compacting the mixture of earth and asphaltum from the bottom upwardly by repeated tampings, a plying more earth and asphaltum onto tle compacted mass, harrowing through the upper layer into the lower layer` of earth and asphaltum, compacting the upper layer from the bottom upwardly by repeated tampings, and applying a sealing substance to the top of the compacted mass.

3. The method of building roadways consisting of forming a base by compacting' the earth between thelines of the roadway and coating the compacted earth with waterrooing material, introducing earth ontothe se, applying` 'a binder' to the introduced earth, harrowm the earth to pulverize the earth andmix t egbi'nder therewith, kneading and tampingthe earth to complete the mixture of the bmdel."y therewith and compact the mixture from thebottom upw'rdly', and applying a sealing substance to the compactedmass'. f y

4l The method of building roadways consisting of forming a base by compacting the earth between the lines of the roadway, introducing earth onto the base, ap- Elying a binder onto theA introduced earth,

arrowing the introduced earth to ulverize the same and mix the ybinder t erewith, kneading andk tamping the mixture to com pact the same from the bottom upwardly,

applying more earth and binder to the compacted mixture, harrowing through the upper layer of earth and asphaltum into the compacted mixture, compacting the har rowed material from the bottom upwardly y tamping, and applying a sealing substance to the' compacted mass.

.of the trench, sealin 5. The method if building highwa s and.

the like, which consists in provi 'ng av trench, compacting the bottom of the trench to seal the capillaries therein, applying a sealin coat over the bottom of t e trench,

xintro ucing earth into the trench applying `asphaltum to the earth, nely dividing the earth, kneading it to impregnate it with the asphaltum, compacting it-from the bottom upward to uni orm density, and applying a top sealing coat to the compacted mass in the trench.

`6. The method of building highways and the like, which consists in removing earth to provide a trench, compacting the bottom the bottom of the trench with a materi impervious to moisture, returning at least some of the removed earth into the trench, applying asphaltum to the earth, finely. dividing the earth in the trench, kneading it to impregnato it with the asphaltum, compacting it to uniform density from the bottom upward, and applying a top sealing coat tc the compacted mass in the trench.

,Inv testimony whereof I aiiix my Signature.

' CALVERT R. HUNT, 

